PRESS RELEASE
3 October 2025

A&O Shearman Advises Genmab On Its Proposed USD8 Billion Acquisition Of Merus

AO
A&O Shearman

Contributor

A&O Shearman was formed in 2024 via the merger of two historic firms, Allen & Overy and Shearman & Sterling. With nearly 4,000 lawyers globally, we are equally fluent in English law, U.S. law and the laws of the world’s most dynamic markets. This combination creates a new kind of law firm, one built to achieve unparalleled outcomes for our clients on their most complex, multijurisdictional matters – everywhere in the world. A firm that advises at the forefront of the forces changing the current of global business and that is unrivalled in its global strength. Our clients benefit from the collective experience of teams who work with many of the world’s most influential companies and institutions, and have a history of precedent-setting innovations. Together our lawyers advise more than a third of NYSE-listed businesses, a fifth of the NASDAQ and a notable proportion of the London Stock Exchange, the Euronext, Euronext Paris and the Tokyo and Hong Kong Stock Exchanges.
A&O Shearman is advising Genmab A/S in its acquisition of Merus N.V., a clinical-stage biotechnology company, in an all-cash transaction with a value of approximately USD8bn.
United States

A&O Shearman is advising Genmab A/S in its acquisition of Merus N.V., a clinical-stage biotechnology company, in an all-cash transaction with a value of approximately USD8bn.

A wholly-owned subsidiary of Genmab, an international biotechnology company headquartered in Copenhagen, Denmark, will commence a tender offer for 100% of Merus’ common shares. The transaction is expected to close early in the first quarter of 2026. The transaction will be funded through a combination of cash on hand and approximately USD5.5bn of new non-convertible debt financing.

The acquisition of Merus, headquartered in Utrecht, The Netherlands, is expected to meaningfully accelerate Genmab’s shift to a wholly owned model, expanding and persifying the company’s revenue, driving sustained growth, and contributing to Genmab’s evolution into a biotech leader.

“We are very proud to be advising Genmab on such a significant transaction that show-cases our cross-border, cross-practice and life sciences capabilities.”

Clare O’Brien

Partner

Capital Markets partner Harald Halbhuber commented: “At a time of enormous change in the global biotech industry, we look forward to continuing to support Genmab as it embarks on the next phase of its growth.”

The A&O Shearman team that is advising Genmab is led by M&A partners Clare O’Brien and Derrick Lott, capital markets partner Harald Halbhuber, debt finance partner Michael Chernick, M&A associate Jake Shaughnessy, capital markets associate Katya Bogdanov, debt finance associate Penelope Yan, antitrust partners Jessica Delbaum and Jonathan Cheng, compensation, employment, pensions and governance (CEPG) partner Doreen Lilienfeld, CEPG counsel Matthew Behrens, tax partner Matthew Brown, and IP transactions partner JB Betker and associate Austin Grossfeld.

Dutch and English law advice is being provided by M&A partners Christiaan de Brauw and Olivier Valk, and M&A associate Bas Sanders, tax partner Rens Bondrager in Amsterdam, and antitrust counsel Jessica Bowring in London.

Contributor

A&O Shearman was formed in 2024 via the merger of two historic firms, Allen & Overy and Shearman & Sterling. With nearly 4,000 lawyers globally, we are equally fluent in English law, U.S. law and the laws of the world’s most dynamic markets. This combination creates a new kind of law firm, one built to achieve unparalleled outcomes for our clients on their most complex, multijurisdictional matters – everywhere in the world. A firm that advises at the forefront of the forces changing the current of global business and that is unrivalled in its global strength. Our clients benefit from the collective experience of teams who work with many of the world’s most influential companies and institutions, and have a history of precedent-setting innovations. Together our lawyers advise more than a third of NYSE-listed businesses, a fifth of the NASDAQ and a notable proportion of the London Stock Exchange, the Euronext, Euronext Paris and the Tokyo and Hong Kong Stock Exchanges.

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